Rates of surgery to correct multilevel spinal curvature in adults ages 60 and older increased by 108% between 2004 and 2011, exceeding the expected growth given the aging population, according to a retrospective analysis of the Nationwide Inpatient Sample (NIS) database. The findings were reported in the September issue of Spine Deformity.
Greatest Increase in Multilevel Fusion Found in 65 to 69 Year Age Group
Increasing rates of multilevel fusion were found in all age ranges, with the greatest rise found among patients ages 65 to 69 years, a cohort that showed an 122% increase from 15.8 to 35.1 cases per 100,000 people.
When separated by the number of levels fused, the rate of surgery to fuse ≥8 levels, while representing only 10.3% of the overall number of cases, increased 237% over the study duration. By comparison, the rate of surgery to fuse 3 to 7 levels increased by 98.4%.
The overall complexity of surgeries used also increased during this period, with greater use of combined anterior and posterior approach, osteotomy, and iliac crest bone grafting found over time, the researchers noted.
Hospital Charges Increased For Multilevel Fusions
Average hospital charges for multilevel fusions increased 108% during this time period—from $90,557 to $188,727 (P<0.001). Average charges were higher when BMP was used ($171,905 vs $125,396 when BMP was not used), and were $132.726 in cases involving bone grafting
Howard S. An, MD
Professor and Morton International Endowed Chair
Director of Spine Fellowship Program
Department of Orthopaedic Surgery
Rush University Medical Center
The clinical implications of these findings are that the older patients are receiving more medical and surgical treatments for their spinal conditions. While it is common to treat the elderly for spinal stenosis or 1-2 level degenerative spondylolisthesis conditions, in the past, surgeons were hesitant to recommend multilevel fusion surgery for the elderly due to associated morbidities.
In addition to the aging population, the other main reasons for the increased number of multilevel fusion cases shown in this study are previous evidence of improved quality of life in older adults following surgery for spinal curvature as well as advances in medicine and surgical techniques made over the past two to three decades allowing larger surgical procedures to be performed with less complications.
It is also true that the number of fellowship trained spine surgeons has increased over the past 2 decades, which may contribute to the increased number of multilevel surgical cases found in this study.
However, the increased number of multilevel fusion cases also could be due to inappropriate selection of patients for surgery. It is my observation that some surgeons “over-treat” degenerative scoliosis, in that multilevel fusion with instrumentation is used when simple decompression or 1-2 level fusion could have been sufficient.
For example, if the magnitude of the spinal curvature is small and the global balance is relatively maintained, decompression alone without fusion is sufficient. If the curvature is moderate and decompression is performed at the level of apex of scoliosis or lateral subluxation, local fusion should be performed at 1, 2 or 3 levels. It is common to find foraminal stenosis at the fractional or compensatory curve from L4 to sacrum in patients with degenerative scoliosis with the apex of the primary curve at the upper lumbar segment, and many can be treated with decompression and fusion at the fractional curve without fusing the primary curvature if the symptom is mainly coming from the fractional curve.
Thus, for the many patients in whom spinal stenosis is the main diagnosis causing neurogenic claudication or radiculopathy, and decompression alone or 1-2 level fusion surgery at the instability levels is adequate to relieve their symptoms. On the other hand, for patients with multiple diagnoses that affect their overall symptoms—including stenosis, instability, and deformity—decompression plus multilevel fusion is necessary to treat both spinal stenosis and deformity.
It should be mentioned that the majority of elderly patients with spinal curvature have degenerative scoliosis without significant global malalignment. In the majority of these patients, observation and non-operative treatments can help reduce pain and symptoms.
I recently presented at national meetings on a series of 100 patients treated with decompression and fusion at the fractional curve, and the outcome was excellent in the majority of patients. If there is severe curvature with coronal and sagittal malalignment, multilevel fusion with instrumentation is justified. Thus, the treatment of degenerative scoliosis should be highly individualized based on many factors. Also, it is important to remember that despite the improvements in medical care and surgical techniques, multilevel fusion with instrumentation in the elderly is still a major undertaking with a high rate of complications.
In summary, the authors should be congratulated for this study, which raises our awareness on the increased number of multilevel fusion cases in older adults. This finding is positive in that the spine surgeons are helping increasing number of elderly patients suffering with low back pain and radiculopathy associated with significant spinal deformity; however, the findings should be interpreted with caution as many spine surgeons might be inappropriately selecting patients for multilevel fusion surgery.
Therefore, the increased use of surgery for spinal curvature in older adults is warranted as long as the surgeons choose appropriate patients for surgery and specific type of surgery.